hints for troubleshooting poor sound quality.

[Lowell Gilbert]

George Hartzell <hartzell at kestrel.alerce.com> writes:

> I've set up an ASUS small form factor machine based around an P4S8L
> motherboard.  It's running 6.0BETA4 and Gnome2.12 from the tinderbox
> packages.
> 
> I'm kldload'ing snd_ich and (after getting a helpful pointer to the
> gnome FAQ) all of the sounds stuff is working.
> 
> Here's my problem:
> 
>   The machine has two mini-jacks, one in the front and one in the
>   back.  If I plug a set of headphones into the front jack I hear all
>   kinds of clicks and whirs and buzzing.  They seem to correlate with
>   drive activity, cd activity, and maybe even the cpu fan.  The
>   connector on the back seems quieter, but I still hear a bit of
>   noise.
> 
>   I hear less noise on a set of sony powerer-subwoofer-and-tweeter
>   speakers, but it's still noticable.
> 
> I haven't been able to try another sound device, the only spare card
> that I have doesn't fit into the space provided (riser card).
> 
> I'd appreciate anythoughts about dealing with the noise.  Is this
> something electrical w/ the motherboard?  Something about my Freebsd
> setup?

Well, yes, it *is* electrical interference on the motherboard.  You
may be able to reduce its impact, though.  Reducing the amplifier gain
(ogain in the mixer(8) output) may help, for example.  Also, does
playing digital audio see this effect, or only playing CDs?  If the
latter, you can switch to digital extraction for playing CDs (most
software doesn't support it, but some does) and avoid the
interference.